My LSAT score jumped from a 159 to a 169. I know I should write an addendum to explain a 10 point jump, but what do they want to hear? I don't have any specific horrible thing that happened to me on the June exam, the October exam just went much better for me. Any specific things I should make sure to say/not to say?

A few schools that I'm applying to have optional additional essays...if I don't have a particularly meaningful or brilliant answer to the question, is it better to just not do the essay? I don't want to look like I rushed through the app or don't really want to attend the school, but I also don't want them to see a lame writing sample. Do those additional essays really matter?